Three-dimensional image display method and apparatus

ABSTRACT

A three-dimensional image display method, includes: displaying a three-dimensional image including a left eye image signal and a right eye image signal displayed at a display focus angle; determining whether to change a viewing focus angle with respect to the display focus angle; calculating a pixel distance between the left eye image signal and the right eye image signal if it is determined to change the viewing focus angle; and displaying indicator marks at positions spaced as much as a half of the pixel distance from a center of a screen in leftward and rightward directions.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from Korean Patent Application No.10-2007-0047089, filed on May 15, 2007 in the Korean IntellectualProperty Office, the disclosure of which is incorporated herein byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Apparatuses and methods consistent with the present invention relate toa three-dimensional image display method and apparatus, and moreparticularly, to a three-dimensional image display method and apparatuswhich displays a three-dimensional image and changes a viewing focusangle of a viewer according to a display focus angle of an objectrecorded in an image source.

2. Description of the Related Art

A three-dimensional image includes a left eye image signal and a righteye image signal which are displayed at a display focus angle. If theleft and right eye image signals are supplied to a display apparatus,the display apparatus sequentially divides the received left and righteye image signals, and displays them thereon. If a person (hereinafterreferred to as a “viewer”) views an image displayed on the displayapparatus by using a device (e.g., shutter glasses) which divides theleft and right eye image signals, the divided left and right eye imagesignals are respectively input to left and right eyes of a viewer. Thus,a viewer may view the three-dimensional image.

If the three-dimensional image is displayed by a three-dimensionaldisplay apparatus, a viewer may perceive precise three-dimensionaleffect only if a viewer views an image with the viewing focus angleidentical to the display focus angle of an object set in an image sourceprovided by a camera or a computer graphic technology. A viewer may losea focus of the three-dimensional image while viewing the image, or mayrepeatedly change a viewing angle until finding a focus to see thethree-dimensional effect. As shown in FIG. 1, if a viewing focus angleF″ of a viewer conforms to a focus angle F′ of an image source, a viewermay see the three-dimensional effect without difficulty. However, if theviewing focus angle F″ of the viewer does not conform to the focus angleF′ of the image source, the viewer does not perceive thethree-dimensional effect and searches for the focus.

That is, left and right image sources form an image on a screen(image-forming screen) 100 at positions L′ and R′ through the displayfocus angle F′. The viewer views the screen 100 at positions L″ and R″through the viewing focus angle F″. Thus, the viewing focus angle F″ ofthe viewer does not conform to the viewing focus angle F′ of the imagesources. The viewer may not perceive the three-dimensional effect untilthe viewing focus angle F″ of the viewer conforms to the focus angle F′of the image sources.

SUMMARY OF THE INVENTION

The present invention provides a three-dimensional image display methodand apparatus which displays a three-dimensional image and changes aviewing focus angle if the viewing focus angle does not conform to adisplay focus angle of an object recorded in an image source to provideprecise three-dimensional effect of an image.

According to an aspect of the present invention, there is provided athree-dimensional image display method, including: displaying athree-dimensional image including a left eye image signal and a righteye image signal displayed at a display focus angle; determining whetherto change a viewing focus angle with respect to the display focus angle;calculating a pixel distance between the left eye image signal and theright eye image signal if it is determined to change the viewing focusangle; and displaying indicator marks on spots in leftward and rightwarddirections spaced as much as a half of the pixel distance from a centerof a screen.

The determining whether the to change the viewing focus angle mayinclude receiving a command to change the focus.

The calculating the pixel distance may include analyzing a displaydistribution of the left and right eye image signals to calculate aphysical distance between the respective display distribution of theleft and right eye image signals according to a histogram, andconverting the physical distance into a pixel distance.

The method may further include storing the indicator marks in advance.

According to another aspect of the present invention, there is provideda three-dimensional image display apparatus which displays athree-dimensional image including a left eye image signal and a righteye image signal displayed at a display focus angle, the apparatusincluding: a display unit; an image signal processor; and a controllerwhich determines whether to change a viewing focus angle with respect tothe display focus angle while the three-dimensional image is displayed,calculates a pixel distance between the left eye image signal and theright eye image signal if it is determined to change the viewing focusangle, and controls the image signal processor to display indicatormarks at positions spaced as much as half the pixel distance from acenter of the display unit in leftward and rightward directions.

The apparatus may further include an input unit which receives a commandto change the viewing focus angle, wherein the controller determines tochange the viewing focus angle with respect to the display focus angleif the command is input through the input unit.

The controller may analyze display distributions of the left and righteye image signals according to a histogram to calculate a physicaldistance between the respective display distributions of the left andright eye image signals, and calculate a pixel distance between the leftand right eye image signals by converting the physical distance into thepixel distance.

The apparatus may further include a memory which stores the indicatormarks therein.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and/or other aspects of the present invention will becomeapparent and more readily appreciated from the following description ofthe exemplary embodiments, taken in conjunction with the accompanyingdrawings of which:

FIG. 1 illustrates a three-dimensional image source whose focus angleconforms or does not conform to a focus angle of a viewer;

FIG. 2 is a schematic view of a configuration of a three-dimensionalimage display apparatus according to an exemplary embodiment of thepresent invention;

FIG. 3 is a flowchart illustrating a method of displaying athree-dimensional image according to the exemplary embodiment of thepresent invention;

FIG. 4 illustrates a histogram of left and right eye image signals if athree-dimensional image is displayed;

FIG. 5 illustrates indicator marks which are displayed at positionsspaced from a center of a screen in leftward and rightward directions,according to the method of displaying the three-dimensional image of thepresent invention; and

FIGS. 6 and 7 illustrate a change of a focus angle (viewing angle) of aviewer according to the exemplary embodiments of the present invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, exemplary embodiments of the present invention will bedescribed with reference to accompanying drawings, wherein like numeralsrefer to like elements and repetitive descriptions will be avoided asnecessary. The present invention, however, may be realized as varioustypes, and is not limited to the exemplary embodiments.

FIG. 2 is a schematic view of a configuration of a three-dimensionalimage display apparatus according to an exemplary embodiment of thepresent invention.

Referring to FIG. 2, the three-dimensional image display apparatusaccording to the exemplary embodiment of the present invention displaysa three-dimensional image which has a left eye image signal and a righteye image signal displayed at a predetermined display focus angle. Thethree-dimensional image display apparatus includes a display unit 210 todisplay an image (e.g., still images, moving images andthree-dimensional images), an image signal processor 220 to process aninput image signal and provide the processed image signal to the displayunit 210, a controller 230 to control the display unit 210 and the imagesignal processor 220, and an input unit 250 through which a viewer caninput a command to change the viewing focus angle.

When the three-dimensional image is displayed, the controller 230determines whether to change a viewing focus angle with respect to thedisplay focus angle. If the controller 230 determines to change theviewing focus angle, the controller 230 calculates a pixel distancebetween the left and right eye image signals, and controls the imagesignal processor 220 to display indicator marks (400L and 400R in FIG.5) at positions spaced as much as a half of the pixel distance from acenter of the display unit 210 in leftward and rightward directions.

The input unit 250 may be provided as a remote controller of thethree-dimensional image display apparatus, or be integrally provided ina main body of the three-dimensional image display apparatus. If thefocus-changing command is input through the input unit 250 by a viewer,the controller 230 may determine to change the viewing focus angle withrespect to the display focus angle. The controller 230 may control theimage signal processor 220 to periodically display a particularindicator mark on the display unit 210 corresponding to the displayfocus angle regardless of a viewer's command. Then, a viewer viewing thethree-dimensional image may view the indicator mark and change theviewing focus angle accordingly.

The controller 230 analyzes display distribution of the left and righteye image signals according to a histogram as shown in FIG. 4 (to bedescribed in detail later) and calculates a physical distance betweenthe display distribution of the left and right eye image signals. Thecontroller 230 may then calculate the pixel distance between the lefteye image signal and the right eye image signal by converting thephysical distance into the pixel distance. The controller 230 maycalculate the pixel distance by using other types of information or datarelated to image signal analysis, instead of using the displaydistribution according to the histogram as described above.

The three-dimensional image display apparatus may further include amemory 240 to store the indicator marks therein. The indicator marks maybe generated and stored in advance or may be generated as necessary.

With the foregoing configuration, a three-dimensional image displaymethod of the three-dimensional image display apparatus according to theexemplary embodiment of the present invention will be described.

FIG. 3 is a flowchart to describe the three-dimensional image displaymethod according to the exemplary embodiment of the present invention.

Referring to FIG. 3, the left eye image signal and the right eye imagesignal of the three-dimensional image are displayed at the predetermineddisplay focus angle (S311).

When the three-dimensional image is displayed, the controller 230determines whether to change a viewing focus angle of a viewer withrespect to the display focus angle (S312). The determination of whetherto change the viewing focus angle is made based on a focus changecommand. For example, if a viewer does not see the three-dimensionaleffect while viewing the three-dimensional image because viewing focusangle of the viewer does not conform to the display focus angle of theimage source and determines that the viewing focus angle should bechanged, a viewer may input the command to change the viewing focusangle through a focus-changing button or key provided in the displayapparatus or a remote controller controlling the display apparatus. Thecontroller 230 may control the image signal processor 220 toperiodically display a particular indicator mark corresponding to thedisplay focus angle regardless of a viewer's command. Thus, a viewerviews the indicator mark and changes the viewing focus angleaccordingly.

If it is determined to change the viewing focus angle at operation S312,the controller 230 calculates the pixel distance between the left eyeimage signal and the right eye image signal (S313).

As shown in FIG. 4, the controller 230 analyzes the display distributionof the left eye image signal and the right eye image signal according tothe histogram to calculate the physical distance D between the displaydistributions of the left and right eye image signals, and convert thephysical distance D into the pixel distance. The image signal processor220 (e.g., a scaler) converts the physical distance D into the pixeldistance. The scaler already knows pixel information (e.g., 1280*720) ofa certain screen (e.g. a screen of high definition TV), and calculatespixels corresponding to the physical distance D if the information onthe physical distance D is received. The image signal processor 220 maycalculate the pixel distance by using other types of information or datarelated to image signal analysis instead of using the displaydistribution according to the histogram as described above.

If the calculation of the pixel distance is completed, the indicatormarks 400L and 400R are respectively displayed at positions spaced asmuch as a half of the calculated pixel distance P from the center C ofthe display unit 210 in leftward and rightward directions (S314), asshown in FIG. 5.

Here, the indicator marks 400L and 400R may be generated and stored inadvance, or may be generated as necessary.

FIGS. 6 and 7 illustrate changing a viewing focus angle of a vieweraccording to the three-dimensional image display method of the presentinvention. If a viewing focus angle does not conform to the displayfocus angle formed by left and right eye images L and R displayed on thescreen 100 (image-forming screen) as shown in FIG. 6, the left and rightindicator marks 400L and 400R are displayed on the screen 100 as shownin FIG. 7. Then, a viewer views the indicator marks 400L and 400R, andchanges the viewing focus angle according the display focus angle formedby the displayed left and right eye images L and R, thereby changing theviewing focus angle. A viewer perceives the precise three-dimensionaleffect of the three-dimensional image by changing the viewing focusangle.

As described above, the exemplary embodiments of the present inventionprovide a three-dimensional image display method and apparatus whichdisplays a three-dimensional image and changes a viewing focus angle bydisplaying a particular indicator mark on a screen if the viewing focusangle does not conform to a display focus angle of an object recorded inan image source.

Although a few exemplary embodiments of the present invention have beenshown and described, it will be appreciated by those skilled in the artthat changes may be made in these exemplary embodiments withoutdeparting from the principles and spirit of the invention, the scope ofwhich is defined in the appended claims and their equivalents.

1. A three-dimensional image display method, the method comprising:displaying a three-dimensional image including a left eye image signaland a right eye image signal displayed at a display focus angle;determining whether to change a viewing focus angle with respect to thedisplay focus angle; determining a pixel distance between the left eyeimage signal and the right eye image signal if it is determined tochange the viewing focus angle; and displaying indicator marks atpositions spaced as much as a half of the pixel distance from a centerof a screen in leftward and rightward directions.
 2. The methodaccording to claim 1, wherein the determining whether to change theviewing focus angle comprises receiving a command to change the focus.3. The method according to claim 1, wherein the determining the pixeldistance comprises analyzing a display distribution of the left andright eye image signals to determine a physical distance between thedisplay distribution of the left and right eye image signals accordingto a histogram, and converting the physical distance into a pixeldistance.
 4. The method according to claim 1, further comprising storingthe indicator marks in advance.
 5. A three-dimensional image displayapparatus comprising: a display unit on which a three-dimensional imageincluding a left eye image signal and a right eye image signal aredisplayed at a display focus angle; an image signal processor; and acontroller which determines whether to change a viewing focus angle withrespect to the display focus angle while the three-dimensional image isdisplayed on the display unit, calculates a pixel distance between theleft eye image signal and the right eye image signal if it is determinedto change the viewing focus angle, and controls the image signalprocessor to display indicator marks at positions spaced as much as halfthe pixel distance from a center of the display unit in leftward andrightward directions.
 6. The apparatus according to claim 5, furthercomprising an input unit through a command is input to change theviewing focus angle, wherein the controller determines to change theviewing focus angle with respect to the display focus angle if thecommand is input through the input unit.
 7. The apparatus according toclaim 5, wherein the controller analyzes display distributions of theleft and right eye image signals according to a histogram to calculate aphysical distance between the display distributions of the left andright eye image signals, and calculates a pixel distance between theleft and right eye image signals by converting the physical distanceinto the pixel distance.
 8. The apparatus according to claim 5, furthercomprising a memory which stores the indicator marks therein.